Abstract

We simulate a two-dimensional incompressible flow around a rotating circular cylinder near a plane wall at the Reynolds number by using the lattice Boltzmannequation with multiple relaxation times. We investigate the flow pattern in the parameter space of the rotational rate and the normalized gap , where is the angular velocity of the cylinder, and are the cylinder radius and diameter, respectively, is the inflow velocity, and is the gap between the cylinder and the wall. We quantify the effects of and on the hydrodynamic forces and the frequency of vortex shedding from the cylinder. Our results indicate that two critical values of , and , exist, which depend on . The flow is steady when , while it has a wake of a regular vortex street when . When , the flow is aperiodic. We observe that the mean drag coefficient is a monotonically increasing function of when . When , is no longer a monotonic function of . The mean drag coefficient varies significantly in the range , and so do the root-mean-square values of the lift and drag coefficients, and . When , the wall effect diminishes.

Received 13 October 2006Accepted 05 April 2007Published online 12 June 2007

Acknowledgments:

We would like to thank an anonymous referee, whose comments help improve this paper significantly. L.-S.L. is supported by the U.S. DOD under the AFOSR-MURI project “Hypersonic transition and turbulence with nonequilibrium thermochemistry” (Dr. J. Schmisseur, Program Manager) and by NASA Langley Research Center under a C&I grant through the NIA Cooperative Agreement Grant No. NCC-1-02043.